Research Needs for Magnetic Fusion Energy Sciences - US Burning ...

in recent years, as the Us community began to focus on iteR diagnostics, ideas for new measurements
arose. With a clear funding path, some of these concepts could be the kernels of proposals
for new burning plasma measurements. The time scale for development of new techniques, from
inception to routine operation, is typically five to ten years. on the other hand, implementing a
new idea for maintenance, robustness, or calibration could occur on a substantially shorter time
scale and potentially be incorporated into ongoing iteR designs. This requires that the development
activity start in the near term (< 2 years). by incorporating minor modifications to “frontend”
components, some systems could be used for multiple measurements, and there are good
ideas to more fully exploit presently credited systems. such expansion of capability could be easily
implemented if modifications are defined early in the development process. as described, to most
positively have an impact on iteR and get the best return on investment, developments should
start as soon as possible.
examples of candidate developments include advanced polarimetry and reflectometry techniques
for local b-field measurements, microwave scattering for density fluctuation measurements, microwave
techniques for fuel-mix measurements, optical Penning gauge measurements of neutral
species in the divertor, methods to monitor and clean optical mirrors, erosion and retention measurements,
remote X-ray sensing for plasma control on demo, and robust in-situ, real-time calibration
techniques.
although developments for iteR require the highest priority, support of measurements for
demo should not be ignored. The environment near the plasma will be much more hostile, and
even higher reliability will be needed. initially, engineering will be needed in the areas of diagnostic
integration with the device and studies of environmental impacts. later, however, work in
preparing prototype instruments for test on iteR will be required.
integration of Thrust Elements
The elements of this Thrust form a coherent program aimed at leading measurement science and
engineering into the burning plasma era. after reviewing iteR measurement capabilities and
risks, an expert panel will define a set of actionable issues. to address these issues, measurement
experts develop and qualify new techniques, which, if successful and applicable, are presented
for implementation. coordination will be beneficial at all stages between those involved in this
Thrust and other diagnostic groups concerned with burning plasmas — most importantly with
the iteR diagnostic division and the diagnostic management groups representing the other domestic
agencies. This coordination could be fostered by including experts from these groups in the
Us expert panels involved in choosing high-priority issues and evaluating the potential of new
techniques. such groups include the diagnostics topical Groups of the Us burning Plasma organization
(and corresponding groups in other nations) and the international tokamak Physics activity.
similarly, there could be coordination with the independent burning plasma diagnostic development
organizations in europe, Japan, and elsewhere.
Relation to Other Thrusts and Other Scientific benefits
This Thrust is focused on the development of diagnostics essential to the control and scientific
mission of burning plasmas. There are important synergies between this Thrust and several other
burning plasma thrusts in this document. measurement needs in other burning plasma thrusts
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